Priming a town with mirrors

Cognitive dissonance research suggests that magnifying the gap between how a person really looks and their ideal state may lead to behavior change. I had the idea of placing full length mirrors all over a community so that overweight and obese people could see themselves the way others do. This is not to be cruel — it may lead to action such as eating smaller portions, exercise and so on. If I add a leading question to the mirror it may further increase temporary discomfort — and change.